After a lot of deliberation I have decided to retire 11th Avenue, it is too heavy and takes too long to setup and take down, but is still in use at home and may still come out to meetings. I will still work on it, got do the fully detailed station.
To replace it will be 23rd Street (the third layout of this name). This is a highly recycled layout, the three straight boards are from the original 23rd Street that lived in my parents loft and came down to exhibitions once or twice a year (I was in my 20's, when doing that was not a problem!).
The boards were 7.4Kg, too heavy, but after removing the Sundeala top and drilling a load of holes in the 12mm sides and 6mm W members I got them down to 4.4Kg.

The track plan

A lot of track but I wanted plenty of operation. A brewery is at the top with a small yard at the bottom. The junction can feed a branch or another industry.
The corner can be attached either way around to give a left or right turn.

The straight boards are now ready for track. They use 11th Avenue's legs (more recycling) with added cross members.

For transport two boards are hinged together to make for faster set up and take down. The pair weigh in at 11.5Kg with end boards, with track etc. should still be under 20Kg.

The third board will stack on top in the trailer. The end boards are from the previous 23rd Street (recycling again). Two hand wheels are used to hold each on.

The corner will use another of my old double track corners (more recycling), Causeway used one, this also folds up, giving three units for the module. The branch board (rebuilt from another old board) will probably be able to fit with the third straight board.
There will only be two joins to connect cables to in the whole module. The wiring and scenery will be much simpler on this module, 11th Avenue was built when we still used D.C.

11th Avenue was built and has evolved to do many things and even works well at home without a fiddle yard. With five joins and extra width it is harder to handle and setup.
23rd Street is a pure single track module only layout, much simpler and only two joins, the other two being hinged with fixed wiring. I'm making it to be as quick to set up as possible. I'm aiming to have no removable panels or structures, so it will be slot the legs in stand it up, put the locking pins in, a couple of connectors and ready to run.
It still has much of the operation ability of 11th Avenue, but without the passenger operations. In addition it has a passing siding and if the branch option is used that makes it even better.

It looks like a great track plan. I understand your decision to retire 11th ave, but 23rd street does indeed make up for a lot of it, and will be a nice new challenge.
What's more you can build it with 'lessons learnt' and it seems you are doing so.

The corner has now been stripped of track and scenery. I have to raise the track bed about 1", widen the ends to 18" and fit new leg pockets. I have to make this board line up with either of its' ends to the straight boards, to allow me to set it up left or right handed.
The module's length means it can go across our meeting room, something we can't do at present. Plus it gives us another 90º corner, with the others that is enough to allow us run up and down the room four times, the branch gives a potential fifth run.

The corner now has a new deck and legs. Major wood work is now complete.

I went with a full width new deck as there will be four tracks running around the corner. It also strengthens the board, although it has survived well over a decade of use so far in its previous use as double track corner.
The legs are the ones used for 11th Avenue and the other corner, they are all interchangeable, the cross brace fits either end as the corner can be used either way around.

Next is to clear enough space to set the boards up so I can make the join to the straight boards.

Most track will be laid on this surface. After laying I cut the drainage ditches into the underlay, and partly strip it down away from the track to give an undulating surface.

I'm raising the mainline slightly by placing it on card strips (the card backing from PECO code 83 turnouts). Spurs will be code 75 to make them lower again.

Track at board joins have 6mm ply strips under them, packed up with card to the correct height. I will Gorilla glue PCB ties on top to hold the track in place.

Another use for the turnout packaging is the clear PVC which I cut to fit between the join while gluing the ply down. I used to use tinfoil, but the PVC being clear allows me to check the heights of the blocks.
It is so clear that it is barely visible in the photo.

And we have track!
The middle pair of hinged boards have most of the track laid.
The mainline is raised on the white card, with the passing siding parallel to it. Top left will be the yard, turnouts are in, the yard tracks will pass onto the next board. The centre beam sits on the team track, a longer industry track will go to the top right. The gondola sits on the RIP / loco spur, it comes off the yard lead, which with the main and siding will continue around a 90º curve towards the camera. The tower is approximately in the final position, its third layout. The track fixing at the board edge can be seen, PCB glued to ply supports.

There are only two turnouts not on these boards, the ends of the passing siding. Next I'll wire the two boards and fit switch motors, I've made sure that turnouts are laid so the motors clear any board supports. The remaining tracks to be laid are those crossing the board joins, probably be code 75. Peco code 75 has too wide ties for the US, but the spurs will be mostly buried in the ballast, I'm not so sure about the yard lead and yard tracks. The wider tie spacing looks better for these tracks and it is lower distinguishing them from the running lines.

One advantage of a portable layout is that it can be turned on end to work on.
I've fitted the switch motors. Six on this board and another six on the one behind.

To check they work I have a change over switch with croc clip leads that I use to temporarily power the motors, it has done many layouts. Here it is powered off 11th Avenue which sits behind.
To check the frog switches I use my old continuity test box made in the first year of my apprenticeship in 1978!
I was using a meter but the contacts showed failure on all I tried. The contacts are not good at very low current, the lamp works much better and only found one that needed tweeking.

The switch motors now have terminals blocks fitted ready for the wiring.

Wiring on the first two boards is complete, here is a view of the underside.
The Conrad switch motors can be seen, with 6 way connector blocks for each one. A pair of Lenz LS150 decoders power the motors.
The big PCB at top left is an 8 way block detector, I've put block detection in from the beginning for automatic signals.
The spiral wrapped wires in the middle are connections between the two hinged boards.
The two orange cables running under and behind the boards are connected to 11th Avenue behind, which is supplying DCC and 16v a.c.

With power applied a loco test runs. I only had one electrical problem, a switch motor shorting as it changed over adjusting the contacts cured that.
The loco lights show power is on.